What's the future of EPC ratings and how does it affect solar panel specification

An Energy Performance Certificate (EPC) assesses a building’s energy efficiency, rating the property on a scale from A (most efficient) to G (least efficient). It also includes information about the building's energy use, typical energy costs and recommendations for improving efficiency.  

EPC ratings are intended to help prospective buyers or tenants understand the cost and environmental impact of heating, lighting and otherwise operating a property. But as the world increasingly recognises the effects of climate change and society starts to take steps towards a more sustainable future, what is in store for EPC ratings, and how will any changes affect solar PV specification? 

A quick history of EPC ratings 

EPCs were introduced in 2002 as part of the European Energy Performance of Buildings Directive (EPBD). They were phased into law in the UK starting in 2007, and by 2009, they were required for any commercial or residential property being bought, sold or rented across the UK. 

Since their introduction, EPC ratings have played an essential role in improving energy efficiency and sustainability of the built environment. Because higher EPC ratings mean reduced running costs, as well as increased property value and appeal, they have encouraged property owners to invest in energy-saving measures such as solar panels, heat pumps, triple glazing and insulation.  

The Future Homes Standard and what it means for EPC ratings 

The Future Homes Standard (FHS) is set to be implemented in 2025. It will aim to ensure that new homes in England produce carbon emissions 75-80% lower than current levels. It will emphasise the use of low-carbon heating systems and renewable energy sources such as solar PV, as well as the increased energy efficiency of the building envelope. While the FHS will apply only to England, similar sweeping reforms are also being introduced in Scotland, Wales and Northern Ireland.  

To meet the ambitious goals of the FHS, EPCs will need to evolve, and the introduction of the Home Energy Model (HEM) is a key part of this evolution.  

The HEM will replace the Standard Assessment Procedure (SAP), which is currently used in the creation of an EPC. The HEM is a more sophisticated approach to evaluating a home’s energy performance. It takes a more granular approach to analysing a property's energy performance, looking at specific household appliance ratings, insulation specifications and the number of occupants. The result should be a more accurate and transparent assessment of a property’s energy use and efficiency. 

At the time of writing (July 2024), it is not clear how the FHS or HEM will ultimately affect EPC ratings. The required minimum ratings could be changed, or an entirely new type of certificate could be created. Most industry experts, however, agree that changes to the EPC are inevitable with the implementation of the FHS in 2025. 

How will changes to EPC ratings and the HEM affect solar panel specification? 

While we await the final iteration of the Future Homes Standard in 2025, the specifics of how these evolving standards will affect solar panel specification are not certain. Still, we can make some assumptions based on resources released as part of the government’s consultation: 

• The Home Energy Model 
• Modelling PV electricity generation and calculating self-consumption within the Home Energy Model 
• The BRE’s sample HEM calculation tool 

We believe the Future Homes Standard will lead to higher demand for solar panel installations. Solar PV may become a mandatory addition in new-build homes, helping to bring down energy bills and reducing our reliance on fossil fuels for heating, lighting, operating appliances and charging electric vehicles. 

As part of this, solar panels are also likely to become a more integrated part of the home, working together with heat pumps, battery storage and smart home systems to use renewable energy more effectively. 

Preparing for the future of EPCs and the HEM with Marley 

The future of EPC ratings, driven by the Future Homes Standard and the Home Energy Model, promises more sustainable and energy-efficient housing. Solar panel specification will need to adapt to meet higher standards and integrate with other technologies, and here at Marley, we’re already working towards these goals. 

At Marley we offer a full solar system for your project including the Marley SolarTile®, solar batteries inverters and EV chargers. To find out more, visit our dedicated renewable solutions page or contact us today.